The question — what would you do? — rode on a wave of outrage in New York City on Tuesday over a harrowing act the day before. An agitated man pushed a 58-year-old stranger onto the track of an oncoming subway train in Midtown Manhattan. The man, Ki-Suck Han of Elmhurst, Queens, was struck and killed.

The episode brought with it something new: pictures, taken seconds before the victim was struck, by a freelance photographer waiting for the train.

The pictures published in the New York Post brought wide criticism and were derided as ghoulish and insensitive. But the pictures’ mere existence started another conversation across the city on Tuesday, summarised by the television weatherman Al Roker, who, on NBC’s “Today Show,” said: “Somebody’s taking that picture. Why aren’t they helping this guy up?”

The police took a suspect in the case into custody Tuesday afternoon at 50th Street and Seventh Avenue. Paul J Browne, the Police Department’s chief spokesman, said Tuesday night that the suspect had implicated himself in the crime. He said that charges were not expected until Wednesday.

The freelance photographer who took the pictures, R Umar Abbasi, defended his actions. “I’m being unfairly beaten up in the press,” he said on Tuesday. Abbasi said he was standing near the 47th Street entrance to the platform when he saw the man fall on the tracks. “Nobody helped,” he said.

Abbasi said he started firing off flashes — 49 times — to warn the driver of the oncoming subway. He estimated the victim was on the tracks for 10 or 15 seconds before he was struck. “The driver said he slowed down because he saw my flashes,” he said.

Abbasi said he brought police officers to the Post’s offices, where editors examined the pictures. He was not part of the decision to publish the pictures, he said adding, “I don’t care about a photograph.”